As two former crewmates who sailed together, many people wonder why Buggy seems to hold a grudge against Shanks even though both of them were very close when serving on the legendary pirate crew, the Gold D Roger. Considering that both Buggy and Shanks were the youngest members of the crew, it makes sense that they became friends after going through many battles together in the One Piece story. Shanks even considered Buggy a friend and even went out of his way to care for Buggy when he was suffering from a mysterious illness while approaching the Laugh Tale island.
During their first meeting after many years at Marineford, Shanks appeared very close to Buggy, but it was only Buggy who still seemed to harbor animosity towards Shanks. Buggy even shouted at the red-haired pirate. The reason behind Buggy’s behavior was revealed in chapter 1082 of the One Piece manga, which featured a flashback during Roger’s execution. It turns out that Buggy held Shanks in high regard and had high hopes for his friend.
Buggy had a dream to follow in Roger’s footsteps and reach the last island, the Laugh Tale, and obtain the mysterious treasure called One Piece. He hoped that Shanks would become the next pirate king and help him achieve his dream. However, Shanks changed his mind, much to Buggy’s disappointment. It wasn’t just because Buggy wanted Shanks to become the pirate king, but because his dream of reaching Laugh Tale was dashed.
The main reason was that Shanks was the one who took away the treasure map. If it was an ordinary treasure map, Buggy would not have been so angry. However, it was most likely the fourth copy of the Road Poneglyph, the map that held the key to reaching Laugh Tale. This was the treasure that could help Buggy achieve his dream of following in Roger’s footsteps.
From their friendship story, Buggy wouldn’t have been so angry if it was an ordinary treasure map. Shanks was probably intentional in removing the copy of the Road Poneglyph so that no one would reach Laugh Tale before he found the successor of Joy Boy. This is why Shanks only moved to pursue the One Piece treasure after Luffy awakened the Nika devil fruit and was recognized by Zunesha as Joy Boy.
It seems that Shanks was already informed by his master Roger that only Joy Boy would be able to find the One Piece treasure. Thus, Shanks decided to act when Luffy was ready to go to Laugh Tale. The friendship between Buggy and Shanks seemed to have been affected by the ambition to find the treasure. What was once a strong bond of loyalty and trust was broken because of their different goals and desires.